Piston actuated hydraulic pressure tool



@Rpt 7@ M54 w. E. Nom'HcUT-n RIsToN ACTUATED HYDRAULIC PRESSURE Toor.

Filed June 20, 1951 3 Sheets-Sheet 1 Nm wm .5MM Q\ ATTORNEYS Set 7 5 W.E. Nom'-HTT E PISTON CTUATED HYDRAULIC PRESSURE TOOL Filed June 20, 19513 Sheets-Sheet 3 @NVENTDR Y @UQT- E Nmr'h EMU ATTORNEYS,

Patented Sept. 7, 1954 PISTON ACTUATED HYDRAULIC PRESSURE TOOL Walter E.Northcutt, Kankakee, Ill., assigner to Manco Mfg. Co., Bradley, Ill., a,corporation of Illinois Application June 20, 1951, Serial No. 232,563

9 Claims. l

The present invention relates to manually operated hydraulic tools, suchas crimping and cutting tools actuated by hydraulic ram, and inparticular to the hydraulic actuating mechanism.

An object of the present invention is to provide a hand operated toolhaving relatively movable dies, cutters, or the like, movable toward oneanother with substantial force to effect bending, forming, crimping,cutting or the like, of hard materials, particularly metals, with theeX- penditure of little physical effort.

Another object. of the present invention is to provide a tool includinga manually operated hydraulic pump adapted to reciprocate a ram orpiston for eiiecting a work stroke or movement of a die, cutter, or thelike, wherein the manual veffort required is slight and the applicationof force to the work piece is great.

Another object of the invention is the provision of a tool including amanually operated two-stage or compound pump for rapidly moving a die orthe like into engagement with the work piece and thereafter slowlymoving said die or the like with respect to the work piece withapplication of ccnsid'erable force to do Work on the work piece. Y

./-i further object ofv the invention is the provision of a completelyself-contained tool, comprising a fluid reservoir, a. iiuid pump and aram movable to effect work, the pump being manually operated andproviding a large mechanical adi" vantage between the operating lever ofthe pump .andthe ram.

A still further object oi the invention is to provide a tool of thecharacter dened in the preceding paragraph having a compound pump ini lcluding a high volume-low pressure unit and a low volumeehigh pressureunit, the tWo units cooperating toprovide rapid. movement of the ram 4to bring a die or the like carried thereby into engagement with the workpiece, the low volumehigh pressure unit thereafter effecting movementof' the ram to apply force to the work piece and perform work thereon.

In addition to the foregoing, it is an object of the 'present inventionto provide a tool of the character described having automatic valvemeans for oy-passing the output of the low pressure pump unit back tothe duid reservoir after the die or the like has been moved intoengagement with the work piece and while the high pressure pump uniteffects the performance of work.

Another object of the invention is to provide in a tool of the characterdescribed, automatic safety valve means for relieving hydraulic pressure2 acting on the ram when the pressure rises to a predetermined maximum.

It is also an object of the present invention to provide a manuallyoperated hydraulic ram for actuating dies, cutters, or the like forperforming Work on a work piece, the pump being of a compound nature andhaving a by-pass valve for one stage of the pump when the ram actuatingpressure exceeds a predetermined value. The hydraulic ram of the presentinvention also includes a relief valve for Venting the ram pressurechamber to the reservoir when the pressure in the ram chamber exceeds apredetermined maximum, a manually operable valve for venting the ramchamber to the reservoir and a pair of handles, one handle beingmanually oscillatable to operate the compound pump and the other beingadapted to eiiect actuation of the last named valve for relieving thepressure in the ram chamber.

Y Another object of the invention is to provide a hydraulic tool havinga pair of handles, one oscillatable to operate a pump to actuate a ramin its working stroke and the other rotatable to operate a valve forventing the ram pressure chamber to a fluid reservoir to accommodate thereturn stroke of the ram.

A still further obj ect of the invention is the provision of a hydraulictool that is compact, operated with a minimum of physical effort,economical of manufacture and maintenance, sturdy and of long life.

Other objects and advantages of the invention Will become apparent inthe following detailed description of a preferred embodiment of theinvention, wherein reference is made to the accompanying drawings, inwhich:

Figure l is a plan View of the tool, a portion of the pump body beingcut away to show the low pressure pump by-pass valve and latch means forthat valve;

Figure 2 is a side View, partly in section and partly in elevation,taken substantially along the line 2-2 of Figure 4;

Figure 3 is a vertical sectional View of the pump mechanism, with theram, the material working members, and the members defining the fluidreservoir, removed, taken substantially along the line 3 3 of Figure 4;

Figure 4 is an enlarged end elevation of the body of the tool, the viewbeing taken from the right hand side of Figures 2 and 3, but showingonly the body;

Figure 5 is a plan view, partly in section, on an enlarged scale, thecross sectioned portion being taken substantially along the line 5-5 ofFigure 4; and

Figure 6 is a partial sectional view of the automatic relief valve takensubstantially along the line 6 6 of Figure 4.

Referring to the drawings, the hydraulic tool of the present inventioncomprises a body I0 dening a pump chamber and a ram chamber, a tool headI2 upon which dies, cutters, or the like are mounted for actuation bythe ram, a pump actuating handle I4, a supporting and valve actuatinghandle I6 and a fluid reservoir I8.

Referring to Figure 2, the body IIIY is preferably an integral steelforging having a main portion that is generally cylindrical and providedat one end with an enlarged cylindrical extension having a bore 2|therein forming a ram pressure chamber or cylinder. The cylindricalextension 26 is provided with an external thread 22 for the reception ofthe tool head I2. At its opposite end, the body I0 is provided with anenlarged cylindrical portion 23 for the reception of the membersdefining the fluid reservoir I8 and is provided with an internal thread24 for securement of those members to the body I0. A cylindrical bore 25is formed in the body along the longitudinal axis thereof, the bore 25being provided at either end with counterbores 26 and 21 communicatingwith the ram chamber 2| and the uid reservoir I8, respectively.

Referring now to Figures 1 and 3, the body I0 is provided, at one sideof the axis of the bore 25, with a cylindrical portion 28 extendingperpendicular to, but laterally spaced from, the axis of the bore 25.The cylindrical portion 28 is provided with a stepped bore 29 defining apair of pump chambers 3U and 3|. A pair of spaced parallel bores 32 and33 are provided in the body In and extend normally to but in verticalalignment with the stepped bore 28 and intersect the pump chambers 30and 3| respectively. Both bores 32 and 33 extend through the body IIJand communicate with the bore 2| and the cylindrical portion 23. Thebores 32 and 33 are provided at each end with counterbores and tappedportions for the reception of valve mechanisms to be describedhereinafter. Vertically aligned with, but spaced from the bores 32 and33, is a valve chamber 34 defined by a counterbore of a bore 35. Thebore 35 is open at the reservoir side of the body I6 and is providedwith a second enlarged counterbore 36 provided with an internal thread31 for the reception of the handle I6. Communicating with the chamber 34is an inclined bore 38 which extends upwardly and toward the center ofthe body I Il from the chamber 34, the bore 33 opening into thecylindrical portion 23, as shown in Figure 4. Communicating with thebore 35 is an inclined bore 39, which extends upwardly and toward thecenter of the body I0 from the bore 35 and opens into the bore 2|.

Immediately below the chamber` 34, as shown in the drawings, the bodyIll is provided with a boss 4G within which a tapped hole 4| is formed,the hole serving as a filling opening for the iiuid reservoir and beingnormally closed by a plug 42 threaded into the bore 4|.

As shown in Figures l and 5, a transverse bore 43 extends from one sideof the body I0 into communication with the bore 32 and thus with thepump chamber 38. Bore 43 is provided at its outer end with a counterbore44 for the reception of a valve to be described in detail hereinafter. Alongitudinal bore 45, spaced from,

but generally parallel to the bore 32, establishes communication betweenthe reservoir and the counterbore 44. The bore 45 opens along its bottomedge into the counterbore 21. A second and smaller bore 46, co-extensivewith an opening along one edge into the bore 45, see Figures 4 and 5,serves to provide a fluid by-pass of a latch member, to be describedhereinafter, normally positioned in the bore 45. Referring to Figures 4and 6, a longitudinal bore 41 extends/ through the body IU from the bore2| to the cylindrical portion 23 and is provided at each end with acounterbore. The bore 41 serves as a relief passage for fluid from theram chamber 2| when pressure therein exceeds a predetermined maximum. Atits upper end, the body I0 is provided with an upwardly extendingportion 48 having a transverse bore 49 therein forming a fulcrum for thehandle I4.

In the preceding description, the body I0 has been described with littlereference to the members to be associated therewith for the purpose ofdefining the structure and formation of the body I0. The parts andmembers to be associated with the body and their association therewithwill now be described.

Slidably mounted in the bore 25 is a piston rod 50 threadedly connectedat one end to a ram 5| deiined by a radial flange having a diameterslightly less than the diameter of the bore 2| defining the ram pressurechamber or cylinder. The flange is slidably received in the bore 2| andforms the head of the ram or piston. Immediately inward from the flange,the ram 5| is provided with a cylindrical portion 52 about which ispositioned an annular sealing ring 53. The sealing ring 53 is generallyof the block-V type and is confined between the cylindrical Wall of thecylinder 2| and the cylindrical part 52. An annular washer 54 isslidably received on the rod 5U and is held against the surface of thering 53 by means of a lock nut 55. The lock nut 55 is slidable withincounterbore 26 of the bore 25 and a seal 56 is positioned in the bottomof the counterbore 26 around the rod 5B to seal off the ram pressurechamber defined between the ram or piston 5| and the bottom of the bore2| and the counterbore 26.

At its opposite end, the rod 5U is provided with a reduced extension anda washer 51 is presstted to a knurled portion of the rod at the innerend of the reduced extension, the Washer 51 being received in thecounterbore 21 of the bore 25. The washer 51 serves as a latch actuatoras will be described hereinafter. At its outer end, the reducedextension is provided with a threaded portion upon which a fianged nut58 is received. A compression spring 59 is confined between the flangednut 58 and a flanged annulus 60 surrounding the rod 50 and seatedagainst the endwall of the body I0. The spring 59 constitutes a returnspring for the hydraulic ram and serves to bias the ram 5| toward thebottom of the pressure chamber dened by the bore 2|.

Referring now to Figure 3, a spring 6| and a ball valve 62 arepositioned in the counterbore on the reservoir side of each of the bores32 and 33. A seat deiining tubular stem 63 is threaded into eachcounterbore and forms at its inner end a valve seat for the ball 62.Each stem 63 is closed at its outer end and is provided with acircumferential groove 64 adjacent its outer end Within which acylindrical screen 65 is positioned. Radial holes 66 establishcommunication between the circumferential groove 64 and the central'boreI or holein` the stem. 63. The spring 6| normallyr holdsv theI balivalve 62 to itsi seat on the inner` end of the stem. 63. In thecounterbore` on: the ram pressure chamber side of. each of the bores 32and 313,v a. ball valve 91' normally sealingly engages a seat` formed bythe counterboreandv isf urged thereagainst by a? compression. spring 69compressed between the ball and` a tubular stem 69 threaded into thecounterbore; Ball valves lf2.- and 61 serve as inlet and outlet check.valves respectively for each of the pump chambers 30"l and 3|.

A pump s1eeve10is threaded intoy the stepped bore 29? and. extendsdownwardly to provide ad,- jacent its lower end a high: volume-lowpressure pump chamber in. the chamber 30'. The bore in the sleeve 10 isstepped-1,` and. ports 1|. are pro.- vided in the sleeve to establishcommunication between the chamber 39 and the lower end of the bore inthe sleeve. Adjacent its upper end, the sleeve 10. is provided,r withA acircumferential groove within which a Neoprene 0- ring seal 12 isreceived? to prevent leakage past the sleeve. At. its upper end, thesleeve 1011s provided with a counterbore 13. within which a Neoprene Oring seal 1:4 is received.. Neoprene is the preferred material for the Oring seals12 and. 14, since Neoprene is not. subject to deteriorationdue tov contact with hydraulic fluids. It is apparent that othermaterials may be utilized for the formation of the O rings and' otherseals as: desired.

A lock nut 15 is threaded into the bore' 29 to lock the sleeve in placeand retain the seal 14 within the counterbore 19. A pump plunger piston16. is-slidably mounted in the sleeve 1.0 and is provided with anenlarged portion slidably mounted in the bore of the sleeve 10 andi areduced end portion extending into the reduced lower end of the bore 291The slioulder on the plunger 116 betweeny the enlarged and reducedportions thereof provides a pump piston.` re.- ciprocable within thebore of the sleeve 10 to comprise a high volume-low pressure pump.

The lower end of the plunger 1t` is reciprocable Y within the reducedlowerI end of the bore 29 to comprise a high pressure-low volume pump.The 0 ring seal 14 sealingl'y gripsthe piston 16 to prevent leakage pastthe piston.A

At its upper end, the plunger. 16- is provided with an enlarged head 11provided with aslot.'|=8 therein for the lose reception of an.`actuating pin 19 connected tothe handle |41 The handle |4- comprises ahead member 90 and. a tubular shank 8|.. The head 80'; consists oiagenerally arcuate forging having parallel but olset end portions joinedby -an arcuate portion'. Handle head 80 is bifurcated, at 82, for thereception oi the upwardly projecting. portion 4B of the body |0. Thebiiurcated portion 82 of the handle |4 is pivotally securedy to the.opstanding portion 481 by a pin 89 extending through aligned bores ineach leg of the bircurcatedv portion 82"v and of the bore 49 in thebodyl portion. 48?. The pin 83 is preferably` provided atone endl' withan integral head 94 and at its' other end with a circumferential. groovewithin whichL a C washer or clip 851 is received to holdE the pin inposition.

The head 11' of the plunger 16 is alsoy received in the bifurcatedportion 82 of' the' handle I4 and is secured therein in a manner similarto the connection of the bifurcated portion 82 and the body portion 48,bythe pin' 19 which has a head 01 and a circumferential groove withinwhich a Cwasher ori clip: 88 is received. The pin1:9.:isfloosely'received'. in the slot 18 to`4 accominodate thehorizontal component. of the oscillation'v ot the handle |'4 in anarcuate path about the pin4 93. When the handle |4 is manuallyoscillated, the vertical component of the movement will beV imparted' tothe plunger 11 and eiiect vertical reciprocation thereof in a pump.-ingv action. The shank 8| of the handle I44 is encased' in a twoepiecetube 90 of insulating material, one piece of which forms a hand grip.9|.

rZChe handle |16 comprises a iirst tubular por'- tionl 92*` threadedinto the counterbore 36 ot bore 35;.with theforward portion of the tube92A being encased in a tube. 93 of insulating'material. Just beyond theendof the tube 193, the tubular portion 92 is provided,.intermediate itslength, with a circumferentiat groove 94. Rotatably mounted on the outerend of the tubular portion 92 is a second metallic tube 95- which isprovided atv its forward edge with an inturned iiange 96v looselyreceived within the groove 94 to. preventdissociation of theA tubularportions 92` and 95. The tubes 92 and 99y are provided with matingthreaded portions 91. The tube 95 is encased in a handle: grip 99 ofinsulating material and is. secured to. a rod' 99 extending coaxiallythrough the tubes 92 and 95 by means of a pin |00 and a. block |0|.. Therody 99: extends through the tubes 92. and 95 and into the counterboreof the bore 35l forming the chamber 34. Adjacent. its forward edge,therod 99 is provided with a circumferential: groove |02 within which anO ring seal |93 is` received to prevent leakage: of fluid past the rod99 from chamber 94. The rod 99 has a reduced? and rounded forward endarranged to. engage a ball valve |94 positioned in the chamber 34. Theball |04 is adapted to be moved to a conical. seatrv |05 formed at the.end of thev chamber 94 to close the port or bore 35. The groovev 94l inthe. tubular handle portion 92 is of a width to accommodate relativelinear movement between the tubes 92 and 95. The threaded portions 91 ofthe tubes' have a large pitch angle so'that the threaded portions 91form a fast thread for moving the rod 99 forwardly and` rearwardly arelatively great distance upon slight rotary movement of' the hand grip98 to seat and" unseat the ball valve |04;

A- ccnical by-pass valve member |06 is slidably positioned intheccunterbore 44 of the transverse bore 491 and is arrangedl to1 close thebore 49. The valve |09 is' held againstconical' seat 91' formed at theinner end ofthe counterbore 44 by a spring |09 coniined. between thevalve and a plug |99 threaded into the counterbore 44. Thev spring |208exerts a predetermined force on thevalve |96 sothat the valveV |06 willbe automatically opened upon attainment of a predetermined pressure inthe pump chamber 90. The conical portion of the valve 09 terminates in acylindrical surface H9 whichI is aligned with the axis of the bore 45when' the1valve is closed, as shown in Figure 5. A bypass latchisslidably mounted in the bore 45v and comprises a cylindrical portion H2sldably received in. the bore 45 and ar reduced noseportion. H3 having arounded end. The end of the nose I |'3 normally engages the cylindricalsurface H0 of thev valve |96` (see Fig. 5) and is urged thereagainst bya spring |'|4 confined between the cylindrical portion I I2 of the latchand the flanged annulus or collar 69. The nose |'|3 of the" latch isadapted 'tov cooperate'with the conical portion' of the valve |06V tocam the valve to full open position under the urge of the spring |I4after the valve |06 has been cracked or partially opened by iluidpressure in the pump chamber 30. The conical surface of the valve andthe nose of the latch constitute cooperating cam surfaces effective tofully open the valve |06 after the cylindrical surface has been movedout of engagement with the nose I I3 of the latch. The latch holds thevalve in open position to establish communication between the chamber 30and the fluid reservoir through the bores 43 and 45. The cylindricalportion |I2 of the latch III extends into the counterbore 21 of the bore25 along one edge and is arranged to be engaged by the latch actuatorwasher 51 on the piston rod 50 on the return stroke of the piston.

Referring now to Figures 4 and 6, a ball valve I |5 is positioned in thebottom of the counterbore of the bore 41 on the fluid reservoir sidethereof. The ball I5 is held against a seat in the bottom of thecounterbore by a plug I I6 and a spring I I 1 conned between the plugIIB and a plug I I8 threaded into the counterbore. The valve I I5 servesas a pressure relief valve for the ram pressure chamber when thepressure therein exceeds a predetermined maximum.

The fluid reservoir is deiined by a resilient sack or bag I I9,preferably formed of Neoprene, having a cylindrical open end. Asimilarly shaped metalli-c dome |20 having a depth slightly greater thanthe normal depth of the sack I I9 surrounds the sack and protects itagainst damage and in addition restricts the amount of expansion of thesack I I9. The metallic dome |20 is provided with a plurality of ventholes to accommodate free expansion and contraction of the resilientsack ||9. Both the sack IIS and the dome |20 are provided with a radialflange |2| and |22, respectively, at their open ends and the flange |2|ofI the sack |I9 is conned between the end wall of the body I0 and theflange |22 of the dome |20 within the cylindrical portion 23 of the bodyI0. An annular nut |23 is threadably engaged with the thread 24 on thecylindrical portion 23 and is screwed down against the flange |22 of thedome |20 to tightly secure the dome |20 and the sack ||9 to the body I0and to effect a seal, by means of the ilange |2| of the sack I I9,between the body I0, the sack ||9 and the dome |20. When mounted on thebody I0, the sack ||9 encloses the piston rod 50, the nut 58, the spring59, the inlet valves 62 and the inlet valve stems 63.

The foregoing description has been directed to the formation,construction and assembly of the various parts and elements of thehydraulic ram and pump. Assuming now that the fluid reservoir is filledby removing the plug 42 and pouring fluid into the reservoir through thebore 4|, the chamber 34 and the bore 38, and that the ram is arranged toengage a work piece, the operation of the hydraulic tool is as follows:The handle grip 99 of the handle i6 is rotated in a clockwise direction,as viewed from the right hand side of Figures 1 to 3, to move the rod 99toward the body I0 to force the valve |04 against its seat |05 to closethe port 35 and bore 39 communicating with the ram pressure chamber 2|.The handle I4 is then oscillated to effect reciprocation of the plunger16. As the plunger 16 is moved in an up stroke, a vacuum is createdwithin the pump chambers 30 and 3| causing the inlet ball valves 62 tobe unseated. As the valves 62 are unseated, a quantity of fluid issucked into the chambers 30 and 3| from the reservoir defined by thesack |I9. 'Ihe screens 65 on the stems 63 serve to prevent the entry ofsolid particles or extraneous material into the pump chambers. As thehandle I4 is moved in its down stroke, the hydraulic fluid in thechambers 30 and 3| is put under pressure until the outlet check valves61 are opened and the fluid is forced into the ram chamber 2 I. Bothpistons are utilized in forcing fluid into the ram chamber 2| and due tothe volume of fluid forced into the chamber, the piston or ram 5| willbe rapidly moved to the left, as viewed in the drawings, against theurge of the spring 59. Upon continued reciprocation, the pressure in thechamber 2| will increase until it is sufficient to effect unseating ofthe valve |06 on a downstroke of the plunger 16. As soon as the valve I06 is unseated, the rounded nose I3 of the latch I I will engage theconical surface of the valve |06 and cause same to be moved or cammedaway from the valve seat |01, thus opening the port or bore 43establishing communication between the pump chamber 30 and the fluidreservoir through the bores 43 and 46. Upon continued reciprocation ofthe plunger 16, the chamber 30 will be bypassed to the iiuid reservoirso that the pump defined by the enlarged portion of the plunger 16 andthe chamber 30 will be ineffectual. Thereafter, pressure will be builtup in the ram chamber 2| solely by the pump defined by the reduced endportion of the plunger 16 and the chamber 3|. This pump is effective toforce a relatively small quantity of iiuid into the ram chamber 2| underhigh pressure. Upon continued oscillation of the handle |4, pressure isfurther built up in the ram chamber 2| by means of the fluids forcedtherein by the reduced lower end of the plunger 16. It is during thislast defined pumping cycle that the hydraulic ram is adapted to performits designated work.

Should the pressure in the chamber 2| exceed a predetermined safemaximum pressure for the material utilized in the construction of theapparatus, the pressure relief valve I5 will be automatically openedagainst the urge of the spring ||1 to vent the ram chamber 2| to thefluid reservoir. The relief valve ||5 will be effective only to reducethe pressure in the chamber 2| to the aforesaid predetermined maximum.In actuality, however, the valve I I5 after being unseated by uidpressure has a greater area thereof exposed to the fluid and due to thisincreased area and the velocity of flow through the bore 41, the valve|I5 will remain unseated until the pressure is somewhat below thepredetermined maximum, at which time the spring ||1 will return the ballI I5 to its seat to close the relief port 41.

In normal operation, or after the relief valve has been automaticallyactuated, the ram cylinder 2| is Vented to the fluid reservoir to allowor accommodate the return stroke of the piston or ram 5| under the forceof the spring 59. Venting of the ram cylinder 2| is accomplished byimparting a slight rotary twist to the handle grip 98 of the handle I6in a counterclockwise direction, as viewed from the right hand end ofthe Figures 1 to 3. Due to the fast thread formed by the threadedportions 91, the rod 99 is moved a suflicient distance rearwardly by aslight twist of the handle grip 98 to permit unseating of the ball valve|04 to accommodate venting of the ram pressure chamber 2| through thebores 39 and 35, the chamber 34 and the bore 38 to the fluid pressurereservoir. As the piston 5| is moved in its return stroke by the spring59, the latch actuator or annulus 51 engages the cylindrical portion 1|I2, yor the shoulder defined between the reduced nose portion I|3 `and.`the cylindrical portion II2, of the ,latch 1|-|,| itc move the latchrearwardly out of engagement with the valve |06, whereupon the valve |06is urged by .the spring |08' into vengagement with its seat |01 to againrender the pump :chamber 30 operative. When the pressure chamber hasbeen completely vented and the piston 5| has been returned to its normalyposition by the Spring 59, the handle grip ,98 isrotated in theopposite direction, clockwise as viewed from the right hand of theFigures 1 `to 3, to again seat the ball |04 whereupon the apparatus isin readiness for repetition of the cycle just described.

The ram I is adapted to carry or be operatively associated with amaterial working mem- .ber which is preferably associated with a worksupporting member or tool head. The tool head may take any one of aplurality of forms, but is preferably in the form of a C-clamp. The C-clamp comprises a generally C-shaped body |24 having at one end thereofan integral cylindrical portion |25 provided with an internally threadedbore |26 adapted to be threadedly connected with the thread 22 of Athecylindrical portion 20 of the body |0. The threaded connection betweenthe body I0 and the C-clamp I2 is particularly or purposely arranged tobe a semipermanent connection in which the clamp |'2 is not readilyremoved from the body I0 but is capable of slight relative rotarymovement with respect to the body I0. As shown in Figures 2 and 3, camslots |21 are formed in the end face of the cylindrical portion and anumber of slots may be provided las desired, but according to thepresent invention, it is preferred that two cam slots be provided,spaced 180 apart. Each slot is identical `having van inclined -surfaceleading into the slot from the bottom, .as shown in Figure 3. A springpressed plunger |28 is mounted in a stepped bore `|29 (see Figure 2) inthe cylindrical portion of the clamp I2 and is urged into the slots |21.A straight wall of the slot, at the upper edge thereof as shown inFigure 3, prevents rotation in one direction but the inclined surfaceacts to cam the plunger |28 out of the slot to accommodate relativerotation in the opposite direction until the plunger |28 slides into theother slot on the inclined wall thereof and engages the straight wall of.that slot to prevent further relative rotation in that direction. It istherefore kseen that the C-clamp |2 is oscillatable in a 180" arc withrespect to the body I0.

The G-clamp may be removed from the body I 0 by reaching into the bore|29 andcatching the spring therein and compressing same with a wire hookor the :like to relieve the pressure on the plunger |28 and thusaccommodate a free rotational movement between the C-clamp I2 and thebody l0 to permit removal of the C-clamp |2. Preferably, the `plunger|28 is provided with a threaded bore (not shown) into which a screw maybe threaded to provide a handle for retracting the plunger from the endface of the portion 20 of the body |0.

The c-clamp |2 is provided with a `bore |30 aligned `with the bore 2| ofthe cylindrical portion 20. An end 'extension |3| of the ram 5| extendsthrough the bore `|30 and is adapted to carry a die, a cutter, or `thelike at its free end.

The C-clamp I2 provides a flat-sided groove |32 for the reception ofdies, cutters, or the like material `working members. Within the upperwall of the Vgroove |32, as viewed in Figure 2,

the C-shaped body portion |24 is provided with a bore |33 for thereception of a pin |315. on one of the material working members |35. Aretainer plate |36 is positioned adjacent the free end of the clamp `I2at the outer side of the groove |32. The plate |36 is provided with apin |31 arranged to 'be received in a bore |38 in the body |24.Intermediate its end, the plate |38 is provided with a hole |39 throughwhich a thumb Screw |40 extends for threaded engagement in a tapped hole|4| in the ybody |24. The pin |31 and the thumb screw |40 serve toretain the ,plate |33 on the body |24 and to prevent relative rotationybetween the plate and the body. The plate |33 has a free end portionextending over the groove |32 and serving to hold the material workingmember |35 in the groove in cooperation with the pin |34. If desired, apin may be provided in the free end of the plate |36 for engagement in arecess in the member |35. The material working member |35 is preferablysubstantially square or rectangular in cross section so as to be firmly`retained against relative rotational Vmovement due to engagement of itsflat or planar sides with the vflat or planar .sides of the groove |32.

To remove the member |35 from the groove |32, the thumb screw |40 `isloosened to such degree that the pin |31 is freed from the bore |33 toaccommodate rotation of the plate |36 about the screw |40. If desired, aspring washer ymay be :interposed between the plate and the body to movethe plate away from the body when the screw is loosened. By turning theplate |35 sideways, the member |35 can be slidably removed from thegroove |32. As is apparent, the member .|35 is stationary and lpresentsa working face adapted to cooperate with the `juxtaposed Vface of amovable material working member..

The member |35 cooperates with a movable member `|42 which iS alsorectangular or square in Vcross section and is arranged to have one hatside Vthereof engaging the flat upper side, as viewed .in Figure 2, ofthe groove |32 to prevent relative rotation between the member |42 andthe C-clamp I2. At the end opposite its work piece engaging face, themember |42 is provided with a bore |43 having a circumferential groove|44 therein. The bore |43 is of such size as to slidably receive the endportion |3| of the ram 5 I.

The reduced end portion |3| of the ram 5I is provided with a diametralbore |45 within which a spring |46 and a pair of balls |41 are received.As the member |42 is slid onto the end |:3I of the ram 5|, the balls |41are cammed inwardly by the edge of the member |42 adjacent the bore `|43against the urge ofthe spring |46l until the balls are aligned with thegroove |44 inthe ybore |43, at which time the balls |41 are forced intothe groove by the spring .|46 to form a ball-type-detent ,for retainingthe member |42 on the end 13| of the ram. If desired, the balls |41 maybe welded vor otherwise secured to the spring |46 to preventdisassociation of the members when the material working member |42 `isremoved from the end |3| of the ram. Preferably, however, the Vmaterialsurrounding the bore |45 at each end thereof is swaged to reduce the.diameter of the bore |45 `after insertion of the spring |46 and theballs |41 to prevent removal of the balls, but to allow the balls toproject slightly from the surface of the ram portion |3I for engagementin the groove |44.

Due -to the fact that balls |41 engage in a groove -in ythe materialworking member, the

member is rotatable with respect to the ram 5I. It is apparent,therefore, that when the clamp I2 is oscillated with respect to the bodyI0, the member |42 will be moved with the clamp I2, and both will rotatewith respect to the body I and the ram To provide means for readilystoring or transporting the tool of the present invention, a resilientring or loop |48 is secured in a known manner to the C-clamp I2.

In operation, a work piece is positioned in the groove |32 of theC-clamp I2 in engagement with the working face of the stationarymaterial working member |35. Thereafter, the hydraulic ram and pump areoperated, as described here inbefore, to bring the working face of thematerial working member |42 into engagement with the work piece. Themember |42 is rapidly moved into engagement with the work piece due tothe rapid movement of the ram 5| under the urge of the fluid dischargeof the two pumps. As the material working member |42 engages the workpiece and commences the performance of work on the work piece, thepressure in the ram chamber 2| necessarily rises to accomplish theperformance of Work. As the pressure rises, the large volume pump(chamber 30) is automatically cut out of operation by the by-pass valve|06, as described hereinbefore, and the high pressure pump independentlyeffects the buildup of pressure in the ram chamber 2| to perform work onthe work piece. When the desired Work has been performed, the pumpingaction is ceased and the hand grip 98 on the handle I6 is given a twistto accommodate opening of the valve |04 to vent the ram pressure chamberto the fluid reservoir. As the ram or piston 5| is returned to itsoriginal position under the urge of the spring 59, the washer 51 on thepiston rod 50 engages the latch I I to move same out of the path of thevalve |06 and the valve |06 is closed by the spring |08 to return theentire mechanism to its original position. The material working member|42 is returned to its original position together with the piston 5| andthe work piece is released and the material working members are clearedfor the reception of another work piece.

In the preferred embodiment of my invention, the tool is adapted forutilization in crimping metallic sleeves about metallic Wires or thelike and in such application, the high volume-low pressure Dump isdesigned for use up to a pressure of 400 pounds per square inch in theram pressure chamber. Upon the attainment of 400 pounds per square inch,the by-pass valve |06 is opened to accommodate relief of the lowpressure pump. Thereafter, the low volume-high pressure pump is designedto build the pressure in the ram pressure chamber up to 10,000 poundswith an approximate manual effort of 40 pounds. Upon the attainment of10,000 pounds per square inch in the ram pressure chamber 2 I, therelief valve |I5 is actuated to vent the chamber 2| to the lluidreservoir until the pressure in the ram chamber 2| is below the maximumpressure of 10,000 pounds per square inch. The handles I4 and I6 areprovided with insulation as described hereinbefore, to render the toolparticularly adapted for crimping sleeves or connectors to live or hotelectrical conductors.

A particular use for which the tool of the present invention is adapted,is the crimping of connectors to high voltage electric power lines. Manypower lines are run through tunnels, and

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in such tunnels, working space is very limited. To render the tool morereadily usable in situations wherein working space is limited, theprovision for oscillation of the tool head I 2 with respect to the pumpbody I0 is made. Such provision renders the tool more convenientlyusable in many situations.

Due to the detailed nature of the construction and operation of the toolof the present invention, the foregoing description has been directed indetail to the exact constructional features of a preferred embodiment ofthe invention. It will be apparent to those skilled in the art thatvarious modifications, changes, and rearrangements can be made in theapparatus Without departing from the spirit and scope of the presentinvention and withoutchanging the end result or function of the tool.For example, in the preferred embodiment, threaded connections areutilized throughout to render the apparatus capable of ready assemblyand disassembly. It will be apparent that other types of connections,such as press-nts, can be substituted for the threaded connectionsreferred to. In addition, the various valve members have beenspecifically referred to as balls, or conical members, or Whateverpreferred construction they take in the preferred embodiment of theinvention. It will be apparent that the exact type of the valve may bevaried or changed as desired, without departing from the spirit andscope of the invention. Therefore, while references has been made tospecific parts, elements and details of construction, the terminologyutilized in the foregoing description and appended claims is to beconstrued as including within the scope thereof all equivalentstructures, parts or elements.

While I have described a preferred embodiment of my invention, it isapparent that various changes, modifications and rearrangements can bemade therein without departing from the spirit and scope of theinvention, as defined by the appended claims.

I claim l. In a hydraulic tool, a pump body having a plurality of pumpchambers, a fluid reservoir, a ram cylinder, said body having inlet andoutlet passages for establishing communication between said reservoirand pump chambers and between said pump chambers and said cylinder,check valves controlling said passages, means for venting one of thepump chambers to the reservoir in response to fluid pressure in said onechamber, comprising fluid passageway means including two passages insaid pump establishing communication between said one pump chamber andthe fluid reservoir, a by-pass valve reciprocably mounted in one of saidpassages, a latch reciprocably mounted in a second of said passages,spring means urging said latch into engagement with said valve, saidvalve and said latch presenting cooperating cam surfaces, spring meansnormally urging said valve to closed position, said last named springmeans exerting a predetermined force on said valve, said valve beingadapted to be opened by fluid pressure in said one pump chamber inexcess of the pressure exertion of said last named spring means, saidlatch under the urge of said first named spring means camming said valveto full open position and retaining said valve in full open positionafter said valve has been opened by fluid pressure in said one pumpchamber, and means for moving upon relief of pressure in said cylinder.

' 2. In a `hydraulic tool, a body having two pump chambers, a fluidreservoir, a ram cylinder, said body having inlet and outlet passagesfor establishing communication between said reservoir and pump chambersand between said pump chambers and said cylinder, check valvescontrolling said passages, pump plungers operable in said chambers,means for operating said plungers in unison, a piston operable in saidcylinder, said body being provided with a pair of angularly relatedby-pass passages establishing communication between one of said pumpchambers and said uid reservoir, a'by-pass valve slidably mounted in oneof said passages, spring means urging said valve to closed position, alatch slidably mounted in the other of said passages, spring meansurging said latch into engagement with said valve, said valve and saidlatch presenting cooperating cam surfaces, said valve being arranged tobe opened by fluid pressure in said one pump chamber when the pressuretherein is Sullicient to overcome said rst named spring means, saidlatch under the urge of said second named spring means camming saidvalve to full open position and retaining said valve in full openposition after said valve has been opened by iiuid pressure in said onepump chamber, and a latch actuator operatively associated with saidpiston and arranged to engage said latch to move said latch out ofengagement with said valve when fluid pressure in said cylinder isrelieved and said piston is returned to its original position, wherebysaid valve is urged to `closed position by said iirst named springmeans.

3. in a hydraulic tool, a body having two pump chambers, ,a fluidreservoir, a ram cylinder, a piston operable in said cylinder, said bodyhaving inlet and outlet passages for establishing communication betweensaid reservoir and pump chambers and between said pump chambers and saidcylinder, check valves controlling said passages, said body having aby-pass for venting one of said pump chambers to said reservoir, twopump plungers operable in said pump chambers, means for operating saidplungers in unison, a normally closed valve controlling said by-passyieldingly urged in closing direction and opened responsive to apredetermined high pressure in said one pump chamber, means forreturning said piston to its retracted inward position, means forretaining said by-pass valve open independently of piston operatinghydraulic pressure in said cylinder, and means for releasing said bypassvalve for closing responsive to retraction of said piston to its inwardposition.

4. In a hydraulic tool, a body having two pump chambers of materiallydifferent diameters, a hydraulic liquid reservoir, a ram cylinder, saidbody having inlet and outlet passages for establishing communicationbetween said reservoir and pump chambers and between said pump chambersand said cylinder, check valves controlling said passages, a pistonoperable in said cylinder yieldingly urged inward thereof, two pumpplungers operable in said pump chambers, means for operating saidplungers in unison, said body having a by-pass for venting the pumpchamber of greater diameter to said reservoir and a vent passage forventing said cylinder to said reservoir, a vent valve normally closingsaid vent passage, means for releasing said vent valve for opening andthereby elfecting venting of said cylinder to said reservoir and returnof said piston from an outer position inwardly of said cylinder, aby-pass valve controlling said by-pass normally yieldingly held closedand opened responsive to a predetermined high pressure in said pump.chamber of greater diameter, latch means effective for retaining saidby-pass valve open independently of piston operating hydraulic pressurein said cylinder after it has been opened and during continued operationof said pump plungers, and means for disengaging said latch means andthereby releasing said by-pass valve for closing responsive to ventingof said cylinder to said reservoir and return of said piston inwardly ofsaid cylinder.

5. In a hydraulic tool, a body having two pump chambers of materiallydifferent diameters, a hydraulic liquid reservoir, a ram cylinder, saidbody having inlet and outlet passages for establishing communicationbetween said reservoir and pump chambers and between said pump chambersand said cylinder, check valves controlling said 'passages, a pistonoperable in said cylinder yieldingly urged inward thereof, two pumpplungers operable in sa-id pump chambers, means for operating said`plungers in unison, said body having a by-pass for Venting the pumpchamber of greater diameter to said reservoir and a vent passage forventing said cylinder to said reservoir, a vent valve normally closingsaid vent passage, means for releasing said vent valve for opening andthereby effecting venting of said cylinder to said reservoir and returnof said piston from an outer position inwardly of said cylinder, abypass valve controlling said by-pass normally yieldingly held closedand opened responsive to a predetermined high pressure in said pumpchamber of greater diameter, latch means effective for retaining saidby-pass valve open independently of piston operating hydraulic pressurein said cylinder, and means actuated by said piston effectiveforreleasing said by-'pass valve from said latch means responsive toreturn of said piston inwardly of said cylinder.

6. In a hydraulic tool, a body having two pump chambers, a liquidreservoir, a ram cylinder, a piston operable in said cylinder yieldinglyurged inward thereof, a piston rod slidable in said body and attached toand movable with said piston, said body having inlet and outlet passagesfor establishing communication between said reservoir and pump chambersand between said pump chambers and cylinder, check valves controllingsaid passages, two pump plungers operable in said chambers, means foroperating said plungers in unison, means for venting one of said pumpchambers to said reservoir comprising a normally closed by-pass valveyieldingly urged in closing direction and opened responsive to apredetermined high pressure in said one pump chamber, latch meanseifective for retaining said bypass valve open independently of thepiston operating pressure in said cylinder, means for optionally ventingsaid cylinder to said reservoir, and cooperating means carried by saidrod and latch means effective for releasing said by-pass valve forclosing responsive to inward movement of said rod with said piston.

'7. In a hydraulic tool, a body having two pump chambers, a liquidreservoir, a ram cylinder, a piston operable in said cylinder yieldinglyurged inward thereof, a piston rod slidable in said body and attached toand movable with said piston, said body having inlet and outlet passagesfor establishing communication between said reservoir and pump chambersand between said pump chambers and cylinder, check valves controllingsaid passages, two pump plungers operable in said chambers, means foroperating said plungers in unison, means for venting one of said pumpchambers to said reservoir comprising a normally closed by-pass valveyieldingly urged in closing direction and opened responsive to apredetermined high pressure in said one pump chamber, a latch memberyieldingly urged toward said by-pass valve engageable therewith forholding it open when said by-pass valve opens responsive to pressure insaid one pump chamber, means for optionally venting said cylinder tosaid reservoir, and a member carried by said rod engageable with saidlatch member for moving the latter out of engagement with said by-passvalve in the inward movement of said rod with said piston.

8. In a hydraulic tool, a body having two pump chambers, a liquidreservoir, a ram cylinder, a piston operable in said cylinder yieldinglyurged inward thereof, a piston rod slidable in said body and attached toand movable with said piston, said body having inlet and outlet passagesfor establishing communication between said reservoir and pump chambersand between said pump chambers and cylinder, check valves controllingsaid passages, two pump plungers operable in said chambers, means foroperating said plungers in unison, means for venting one of said pumpchambers to said reservoir comprising a normally closed by-pass valveyieldingly urged in closing direction and opened responsive to apredetermined high pressure in said one 'pump chamber, a latch memberadjacent and substantially parallel with said rod yieldingly urgedtoward said by-pass valve engageable therewith for holding it open whensaid by-pass valve opens responsive to pressure in said one pumpchamber, means for optionally venting said cylinder to said reservoir,and a member carried by said rod engageable with said latch member formoving the latter out of engagement with said by-pass valve in theinward movement of said rod with said piston.

9. In a hydraulic tool, a body having two pump chambers, a liquidreservoir, a ram cylinder, a piston operable in said cylinder yieldinglyurged inward thereof, a piston rod slidable in said body and attached toand movable with said piston, said body having inlet and outlet passagesfor establishing communication between said reservoir and pump chambersand between said pump chambers and cylinder, check Valves controllingsaid passages, two pump plungers operable in said chambers, means foroperating said plungers in unison, means for venting one of said pumpchambers to said reservoir comprising a normally closed bypass valveyieldingly urged in closing direction and opened responsive to apredetermined high pressure in said one pump chamber, said by-pass valvecomprising an inner tapered portion and an outer straight portion, alatch member adjacent and substantially parallel with said rodyieldingly urged toward said by-pass valve, said latch member comprisinga body portion and a reduced nose portion disposed to contact said outerportion of said by-pass valve when the latter is closed and to contactthe tapered portion of said by-pass valve when it is opened by pressurein said one pump chamber, said nose of said latch member cooperatingwith said tapered portion of said by-pass valve for moving the latter tofull open position and retaining it in that position, and a membercarried by said rod engageable with the body portion of said latchmember for moving the latter out of engagement with said by-pass valvein the inward movement of said rod with said piston.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 2,044,857 Pfauser June 23, 1936 2,096,574 Denny Oct. 19, 19372,134,773 Arp Nov. 1, 1938 2,165,504 Pfauser July 11, 1939 2,250,551Pfauser July 29, 1941 2,311,468 Pfauser Feb. 16, 1943 2,417,956 StromMar. 25, 1947 2,555,421 Ronan June 5, 1951 FOREIGN PATENTS NumberCountry Date 432,823 Germany Apr. 19, 1925

